Eryri (Snowdonia)
Monday 31 August 2026 · Yr Wyddfa, the Glyderau and the Carneddau
Why: Thunderstorm timing is inherently uncertain and may shift by several hours.
Thunderstorms are the main concern, especially on exposed summits and ridges. A noticeable westerly breeze and Persistent rain.
High-ground wind (900 m)
Westerly around 20 mph at 900 m. Gusts reaching around 30 mph at 900 m, with locally higher values possible on the most exposed tops. Strongest early (around 20 mph), easing toward 10 mph later.
Walking impact
Noticeable on exposed ground, but unlikely to impede most walking.
Thunderstorms
A moderate thunderstorm risk is indicated during the morning. Avoid committing to exposed summits or ridges while storms are building or nearby.
Ground conditions
The ground is likely to be wet after recent rain.
Spate risk
There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. The heaviest rain is expected early in the day. Crossing risk is expected from around 04:00 until around 20:00. Turn back if a crossing looks unsafe.
Rain and showers
Persistent rain for much of the day. The heaviest rain is expected early in the day.
Cloud-free summits
Around 30%. Around 25% early, improving to around 40% later.
Cloud and visibility
Cloud bases mostly around 900-1200 m. Bases should tend to lift as the day goes on. Cloud bases are likely to remain high, but some forecast models are much cloudier, so more extensive summit cloud remains a credible outcome. Cloud is likely to come and go on the higher summits; breaks may be useful but not dependable.
Temperature and wind chill
Around 7°C at 900 m, feeling like 3°C in the wind.
Freezing level
Above the summits.
Daylight
Sunrise 06:23 — Sunset 20:08 — about 13.8 hours daylight.
Overnight · 6 p.m.–9 a.m.Wild campingBetaThunder risk is around 31% in parts of the area; avoid exposed pitches if storms develop. 54/100Mixed · 600 m View detailsHide details
Full regional overnight outlook
Across representative hills, open-hillside camping looks mixed around 600 m (54/100). Some overnight rain is likely, so expect a damp pitch or pack-up.
Elevation reference (open ground)
- Wind / gust
- 8 / 18 mph
- Coldest
- 10.7°C
- In cloud
- Unlikely
- Condensation
- Low
- Wind / gust
- 9 / 22 mph
- Coldest
- 10.4°C
- In cloud
- 25% of night
- Condensation
- Low
- Wind / gust
- 10 / 26 mph
- Coldest
- 8.3°C
- In cloud
- 25% of night
- Condensation
- Low
Open-hillside guidance across representative hills. Local shelter, ridges, tent design and the exact pitch can change conditions substantially. How to use the wild-camping forecast.
Daytime · exposed rockClimbing & scramblingBetaThunder risk is around 30% in parts of the area; exposed scrambling may be a poor choice. 0/100Poor · Very poor View detailsHide details
Full regional climbing & scrambling outlook
Conditions for exposed scrambling across the area look very poor (0/100). Rain is likely to leave rock wet; polished slabs, vegetation and drainage lines may be notably worse. Gusts may reach about 30 mph on exposed ground, making crosswinds an important route consideration. Mapped summit-point geology across the representative hills includes volcanic rock and slate or mudstone; moisture response can therefore vary substantially between crags and routes.
Representative summit-point samples across the region; individual crags and routes may differ.
Generic exposed hands-on-rock terrain across representative summits; mapped summit-point geology is a broad regional sample, not a named-route survey. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.
Updated 30 August 2026 at 04:40 UTC. See typical weekly and monthly conditions for Eryri (Snowdonia).